Digital x-ray systems can occasionally generate artifacts that appear on x-ray images. The artifacts can be pixels or collections of pixels that have pixel values (i.e., brightness/darkness levels of the pixel) that do not properly reflect the object being imaged. The artifacts can be caused, for example, by panel defects in the imaging device or x-ray detector (e.g., a flat panel x-ray detector), or as an effect of the x-ray detector equipment, such as the butting gaps of multi-wafer tiling. In this manner, the artifacts can appear as a “bad line” of pixels that have a pixel value generally darker or lighter than the surrounding pixels. The bad lines can inhibit the clarity and viewability of the x-ray image. For example, FIG. 1 shows an exemplary x-ray image having vertical bad pixel line 10, and multiple horizontal bad pixel lines 20.
Bad lines can be corrected by estimating a pixel value for each pixel of the bad line. That is, the value of the bad line pixel can be interpolated by averaging the pixel values of one or more neighboring “good” pixels. For example, where a bad pixel has two neighboring good pixels, the bad pixel value can be substituted with a pixel value equal to the average of the two neighboring good pixels. In this manner, the estimated pixel values can cause the image artifact or the bad lines to diminish or become less noticeable to the human eye.
The interpolation process, however, can affect the statistical property such as the standard deviation or variance of the corrected pixels. That is, because the interpolation process averages the pixel values of one or more pixels the corrected pixels will have a standard deviation that is different from the neighboring good pixels. As a result, certain applications that may rely on pixels having a certain degree of variance, such as peak opacification applications, can be negatively affected by the interpolation process. Accordingly, additional and/or alternative techniques may necessary in order to satisfactorily correct image artifacts or bad pixel lines used in these applications.